1. Field of the Invention
Embodiments relate to an interference alignment (AI) method for an uplink in a wireless local area network (WLAN) system, an access point (AP) and a user terminal for performing the same.
2. Description of the Related Art
A near field communication network, for example, a local area network (LAN) is generally classified into a wired LAN and a wireless LAN (WLAN). In the WLAN, communication may be performed on a network using radio wave in lieu of using cable. The WLAN has been proposed as an alternative for outperforming difficulties in maintenance and repair, movement, and installation of cabling. Due to an increase in mobile device users, the need for the WLAN is also increasing.
A WLAN system includes an access point (AP), and a user terminal. The user terminal may also be referred to as a station (STA). The AP is a device for transmitting a radio wave in order that the user terminals are available to use network or access Internet within a service range. The WLAN system uses an IEE 802.11 standard released by an institute of electrical and electronics engineers (IEEE).
A basic constituent block of an IEEE 802.11 network is a basic service set (BSS). In the IEEE 802.11 network, there is an extended service set that extends a service area by connecting an independent network, for example, an independent BSS, to an infrastructure network, for example, an infrastructure BSS. In the independent network, terminals within the BSS may perform direct communication with each other. In the infrastructure network, an AP may be involved in communication performed between a terminal and another terminal existing inside or outside the BSS.
In general, an IEEE 802.11 based WLAN system may access a medium based on a carrier sense multiple access/collision avoidance (CSMA/CA) scheme, and each AP may operate independently. Thus, in the WLAN system, the AP may independently select a channel using an operator or a channel allocation algorithm. Due to this, a communication channel used by each BSS may overlap when many WLAN systems are provided. When the communication channel overlaps, interference may occur among adjacent BSSs thereby reducing network performance. Therefore, a communication method of effectively reducing the interference occurring in the WLAN system is needed.